Overview
The ZF 4166.339.247 CIRCUIT COVER is a precision-engineered OEM genuine component designed for the WG 65 Series transmission. This cover serves as a critical sealing and protective barrier for the hydraulic control circuit, ensuring that pressurized transmission fluid is directed correctly through the valve body assembly. By maintaining a secure seal, it prevents contamination ingress and fluid loss, which are essential for consistent clutch engagement and torque converter operation. The part number 4166.339.247 is directly interchangeable with the original factory specification, guaranteeing a perfect fit when replacing a worn or damaged unit. This cover is typically mounted adjacent to the TRANSMISSION HOUSING, where it interfaces with the main hydraulic passages.
Symptoms of Failure
When the ZF 4166.339.247 CIRCUIT COVER begins to fail, operators may notice several distinct performance issues. One of the most common symptoms is external hydraulic oil leaks around the cover perimeter, often visible as drips or wet spots on the transmission casing. Another indicator is erratic or delayed gear engagement, particularly when shifting between forward and reverse, as the loss of circuit pressure affects clutch pack actuation. You might also experience intermittent transmission slipping under load, caused by insufficient hydraulic pressure reaching the clutches. Finally, a persistent low fluid level warning or the need for frequent top-ups can signal that the cover seal has degraded, allowing fluid to bypass the intended circuit.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number / SKU | 4166.339.247 |
| Material | Die-cast aluminum alloy with corrosion-resistant coating |
| Overall Dimensions (approx.) | 180 mm x 120 mm x 25 mm |
| Weight | 0.85 kg (1.87 lbs) |
| OEM Reference | ZF 4166.339.247 (Genuine) |
| Sealing Surface Finish | Ground flat to 0.05 mm tolerance |
| Operating Temperature Range | -40°C to +120°C |
Compatibility
This ZF 4166.339.247 CIRCUIT COVER is primarily engineered for the WG 65 Series transmission family. Based on its design and hydraulic circuit layout, it is also compatible with select models in the WG180, WG200, and WG240 series that share the same valve body architecture. Always verify the casting numbers on your existing cover before installation. For a complete assembly, this cover is secured using HEXAGON SCREW (0636011038) and HEXAGON SCREW (0636011118) fasteners, while the main housing attachment requires HEXAGON SCREW (0636016015).
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4616101059 | TRANSMISSION HOUSING | Main structural casing for gear and shaft assembly |
| 0636011038 | HEXAGON SCREW | Fastener for circuit cover mounting |
| 0636011118 | HEXAGON SCREW | Secondary fastener for cover retention |
| 0636016015 | HEXAGON SCREW | Housing-to-cover attachment bolt |
| 0631306085 | CYLINDRICAL PIN | Alignment dowel for cover positioning |
| 0634313118 | O-RING | Seal between cover and housing |
| 0636304019 | SCREW PLUG | Port closure for pressure testing |
| 0634801152 | SEALING RING | Copper washer for plug sealing |
| 0732611049 | FILTER INSERT | Hydraulic fluid filtration element |
| 0634303718 | O-RING | Secondary seal for filter housing |
